The present invention generally relates to a solid image pickup apparatus having a microlens.
A structural sectional view of the conventional solid image pickup apparatus will be described in FIG. 3. A light receiving portion 3 and a transfer portion 4 are provided on the surface portion of a P well region 2 on a N type semiconductor basic plate 1 as shown in FIG. 3. A silicon oxidizing film 5 is accumulated in these upper positions. A polysilicon electrode 6 is provided in the upper portion thereof. A silicon oxidizing film 5 is accumulated even on the polysilicon electrode 6. A tungsten silicon 7 is provided in the upper portion thereof. A BPSG film 8 is accumulated in the upper portion of the tungsten silicide 7. A light screening metal 9 is provided in the upper portion thereof so that light is not projected into the transfer portion 4. A flattening film 10b is provided on it with an acrylic resin or the like.
A microlens 11 is provided on the above described flattened film 10b with the use of a transparent resin being almost the same in refractive index as that in a flattened film material so as to improve the usage ratio of the incident light. Therefore, a substantial opening ratio is improved.
FIG. 4 shows a sectional view of an optical system mechanism such as camera and so on. In FIG. 4, reference numeral 12 is an optical system lens, reference numeral 13 is an iris, reference numeral 14 is a solid image pickup apparatus.
A solid image pickup apparatus 14 is positioned, as shown in FIG. 4, in a location where lights are gathered with the optical system lens 12 to make an image. An image is made as shown in FIG. 4 (a), (b) with the size of the opening portion of the iris 13 in this case. In the case of FIG. 4 (a), lights are collected into the light receiving portion 3 as shown in an incident light passage in FIG. 4 (a) of FIG. 5 (a). An image making position of the microlens 11 is slid sideways from the light receiving portion 3 because of obliquely incident lights, as shown in the incident light passages in FIG. 4 (b) of FIG. 5 (b), in a condition with the iris being opened as shown in FIG. 4(b). As the opening portion of the iris 13 becomes larger like this, the light collecting ratio by the microlens 11 is reduced.